Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Qual é o oponente, quando os rebotes altos são "Pierson (6)"?
 ###Tabelas: CREATE TABLE ethnicities_by_region (ethnicities_by_region_id AUTO_INCREMENT PRIMARY KEY, State VARCHAR, White (%) INT, Brown (%) INT, Black (%) INT, Asian or Amerindian (%) INT) CREATE TABLE ministry_of_higher_education (ministry_of_higher_education_id AUTO_INCREMENT PRIMARY KEY, Name in English VARCHAR, Name in Malay VARCHAR, Acronym VARCHAR, Foundation VARCHAR, Location VARCHAR) CREATE TABLE seasonal_ratings_broadcast_history (seasonal_ratings_broadcast_history_id AUTO_INCREMENT PRIMARY KEY, Season INT, Network VARCHAR, Time slot VARCHAR, Season premiere VARCHAR, Season finale VARCHAR, Episode count INT, TV season VARCHAR, Season rank VARCHAR, Viewers (in millions) INT) CREATE TABLE iran (iran_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Venue VARCHAR, Result VARCHAR, Competition VARCHAR, Goals INT) CREATE TABLE regular_season (regular_season_id AUTO_INCREMENT PRIMARY KEY, Game INT, Date VARCHAR, Opponent VARCHAR, Score VARCHAR, High points VARCHAR, High rebounds VARCHAR, High assists VARCHAR, Location/Attendance VARCHAR, Record VARCHAR)  
SELECT Opponent FROM regular_season WHERE High rebounds = pierson (6)